Lubricant



Patented Aug. 1, 1m

LUBRICANT Lnthony Francis Benning, Penna Grove, N. 3..

assignor to E. I. du Pont de Nemours 8; Company. Wilmington, DeL, a corporation oi Delaware No Drawing.

Application May 7, 1930,

Serial No. 78,409

13 Claims.

This invention relates to lubricantsand particularly to the inhibiting of corosion by lubricants.

In recent years there ha been a marked tendency toward the use of bearing alloys which are not 01' the Babbitt type. Prominent among the newer alloys in use are those consisting essentially of cadmium and silver and known to the trade as silver-cadmium bearings. These bearings have advantages over the older Babbitt types n particularly because of their greater hardness and strength permitting the use of smaller bearings operating at higher unit bearing loads. I

The general use of these bearings is, however,

seriously hampered by their lack of resistance to 15 corrosion when usedin combination with certain mineral lubricants. This undesirable condition is particularly serious because many of the lubricants which have the much desired properties of high viscosity index, low pour point, freedom from sludge and high stability have the undesirable property of being highly corrosive to silver-cadmium bearings.

An object of the present invention is to provide materials which, when added to lubricating oils reduce the tendency of the oils to corrode silvercadmium bearings. Another object is to provide, in combination with a bearing metal'of the cadmium-silver bearing type, means for lubricating such bearings comprising a lubricating oil having incorporated therein a material which will inhibit corrosion of the bearing metal by the oil. Further objects are to provide new compositions of matter and to advance the art. Still Y further objectswill appear hereinafter. I 5 These objects may be accomplished in accordance with my. inventionwhich comprises employing, in combination with a bearing metal of the cadmium-silver alloy type, means for lubricating the bearing metal which comprises a' lubricating oil normally tending to corrode said bearing metal and having incorporated therein in an amount sumcient to inhibit said corrosion an organic ester of a phosphoric acid. This invention is based upon the discovery that oils, which are 5 particularly corrosive toward silver-cadmium bearing metals, can be tremendously improved by the addition to the oil of small quantities of alkyl or aryl phosphates. We have also found that the corrosiveness of oils, which are generally 59 considered satisfactory for use with these bearings, can be further improved in this respect by the addition or similar compounds.

- Examples of the effect ofthe addition of these compounds to oils of considerably diiferent type s are given in the table below.

The method or testing the corrosiveness was as follows:

A sample of the oil to be tested was placed in a large glass test-tube which was immersed in a bath kept at a temperature of 350 F. A glass tube connected to an air supply was inserted in the test-tube. The oil was then placed in the test-tube and weighed strips 0! the metal to be tested suspended in the oil. When the test oil reached the proper temperature, air was bubbled into the oil at a rate 0t 10 liters per hour. After '12 hours, the test pieces were removed, washed free of oil and weighed. The loss in weight is re-v corded in mgJsq. in.

Oil A Saybolt Universal viscosity (at 100 F.) 3030 Saybolt Universal viscosity (at 210 F.) 145 Viscosity inde Pour point IL- 25 Oil A represents the type which has caused considerable trouble from corrosion of silver-cadmium bearings.

Oil B Saybolt Universal viscosity (at 210 F.) so Saybolt Universal viscosity (at F.) 633- Viscosity inde 40 Pour po'm F..- 5

- 60 Change in weight of. test piece mm/sqin; in 72 hOIH'S Plus 17 Plus 17 N 0 ad- 0 com compound dition Pd on A so 7 '21 Oil B 47 35 4 Other compounds which may be employed in accordance with my invention are:

Dilauryl phosphate Dicetyl phosphate Dicycloheiql phosphate pioleyl phosphate Trinaphthyl phosphate pl-LbroP phosphate Lecithin A mixed phosphate ester of"Iiorol" and Ocenol lt-Naphthylamine salt of di-Lorol phosphate I Dilauryl dithio phosphate Diethyl phosphate Triethyl' phosphate Mixed cyclohexyl-cyclohexyl phosphates Tri-Ocenol phosphate Tributyl phosphate Dioctyl phosphate Mixed octyl lauryl phosphate (di-ester) Tri-methylricinoleyl phosphate Lauroxy-ethanol phosphate The monophosphate of the diglyceride obtained. by partial hydrolysis of linseed oil Mixed "phosphate esters 0! hydroxy stearic acid Di-phenyl' phosphate Di-cresyl phosphate Tri-nitrophenyl phosphate Mixed tertiary amylphenyl phosphates Mixed dodecahydro-diphenylol p r o p a n e phosphates Mixed monophosphates Mixed tetrahydro-p-naphthyl phosphates Di- L0rol cresyl phosphate Dibutylamine salt 01' mixed phosphates of and di-decahydro-p-naphthyl lllnrolii I Benzylamine salt of 'mixed phosphates of III-01.01! Amylamine salt 01 mixed phosphates oi.

Lorol Mixed monoand di butyl phosphates Dilauryl trithio phosphate v Diamyl dithiophosphate Triphenyl monothiophosphate Dioleyl dithio orthophosphate Tristearyl dithio orthophosphatej Trimyristyl monothio orthophosphate Monomyristyl monothio metaphosphate Monocetyl monothio orthophosphate 'Irilauryl trithio orthophosphate Dicetyl monothio orthophosphate Tetracetyl dithio pyrophosphate Trilauryl tetrathio orthophosphate 'I'etramyristyl trithio pyrophosphate Tetraeicosyl pentathio pyrophosphate Tri-hexoxyphenyl phosphate Methyl diphenyl monothio phosphate Ethyl diphenyl monothio phosphate Dimethyl phenyl monothio phosphate Methyl dicresyl monothio phosphate Trilauryl monothio orthophosphate Mono decyl monothio phosphate Tricresyl monothio phosphate Tricresyl dithio phosphate Tricresyl trithio phosphate Triphenyl dithio phosphate Triphenyl trithio phosphate Triphenyl tetrathio phosphate Tricresyl tetrathio phosphate Dicresyl dithio phosphate Diphenyl dithlo phosphate I Trinaphthyl monothio phosphate atoms, having chain alkyl" as employed herein will (3) Di-naphthenyl ortho phosphate (3) Di-naphthenyl dithio phosphate (1) This is a mixture of phosphates obtained by reacting an esteriiying derivative of orthophosphoric acid with the mixture of primary normal aliphatic alcohols of 8 and 10 carbon atoms resulting from the carboxylic reduction ofcoconut and/or palm kernel oils and known as Lei-o1" alcohols.

(2) Ocenol comprises a mixture of primary aliphatic alcohols containing 12 to 18 carbon an iodine number oi about 50 and is mostly oleyl alcohol.

(3) These are mixed esters prepared from the mixture oi alcohols obtained by the carboxylic reduction oi. the naphthenic acids from petroleum. Y

- Similar compounds may be prepared from other alcohols such as decyl, undecenyl, ceryl eleostearyl, linoleyl, ricinoleyl, abietyl, cyclohexanol, ethyl octyl, tertiary'amyl, butyl, propyl, benzyl, dodecahydro-diphenylol-propyl, naphthehyl, and mixtures thereof, particularly mixtures obtained by carboxylic reduction of naturally occurring iatty oils. Other aromatic esters may be prepared i'rom phenol, phenols, alkoxy-phenols, hexoxy-phenols, decahydro-naphthols, tetrahydro naphthols and the like. Still other compounds may prepared from the aliphatic and aromatic merc \tans corresponding to the above alcohols and plienols.

cresols, naphthols, nitro- Other-compounds containing two or more diii'erentaliphatic or aromatic radicals or both aliphatic and aromatic radicals may be employed.

The mono- 'diand tri-esters corresponding with those heretofore mentioned may also be mentioned. Esters of phosphoric acid will be obtained by the treatment of a mineral or natural oilwith the appropriate phosphorus halide and a catalyst such as an aluminum chloride.-- The -estersoi the'various normal phosphoric acids may sulphur to form the cor-- also be'reacted with responding thio esters. Phosphate esters can also be obtained by the treatment of oils containing ethylene linkages or hydroxyl groups with phosphorus halides, oxy-halides, oxides, P289, P801: PzSsIBn and the like. Likewise, oils containing mercaptans may be treated with phosphorus halides, oxy-halides, oxides, sulphides and the like to produce similar compounds. The resulting esters will be found to be effective for my purpose and to come within the scope of my invention.

01' the salts which may be employed in accordance with my invention the most eiiective or desirable will be the amine salts of the acid-esters of the acids 01 phosphorus, such as the acidester salts of the methyl amines, ethylamines, ethanol amines, propyl amines, butyl, amines, particularly the dibutyl amines,- amyl amines, benzylamines, aniline, nitroaniline, naphthylamine and other aromatic amines, pyridine, quinoline and similar amines. Examples of such amine salts are the p-nitro aniline salt of dilauryl dithio phosphate and the'pyridine salt 01' dilauryl phosphate. 1/

The terms long-chain aliphatic and "longbeunderstood to mean aliphatic or allwl radicals of at are also well known and described in the literaaremsc'z,

ture. Other compounds of my invention can be prepared by the methods described in the literature. These methods generally comprise the treatment of alcohols, unsaturated aliphatic compounds or phenols with phosphorus chlorides or with phosphorus oxy-chlorides or oxides. Suitable methods of preparing other compounds of our invention are described in Patents 1,748,- 619, 1,889,943, 1,945,183, 1,982,903 and the dopending application of Salzberg and Werntz filed February 19, 1935, Serial No. 7,126. Accordingly, a more detailed description of the methods to be employed for making the compounds referred to in this application isbelieved to be unnecessary.

While I have disclosed specific embodiments of my invention, it will be readily apparent to those skilled in the art that many modifications and variations may be made therein without departing from the spirit thereof. Accordingly, the scope of my invention is to be limited solely by the appended claims, construed as broadly as is permissible in view of the prior art.

I claim:

1. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount suificient to inhibit said corrosion, an organic ester of the phosphoric acid.

2. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of. which is an alloy formed chiefy of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount sufiicient to inhibit said corrosion, an organic ester of a phosphoric acid in which the organic radicals consist of carbon and hydrogen.

3. A method of lubricating bearing surfaces which comprises maintaining between the bear ing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the efiectiveness of the lubricating oil by incorporating therein, in an amount sufflcient to inhibit said corrosion, an organic ester of an orthophosphoric acid.

4. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the efiectiveness of the lubricating oil by incorporating therein, in an amount suflicient to inhibit said corrosion, an organic ester of an orthophosphoric acid in which the organic radicals consist of carbon and hydrogen.

5. A method of lubricating bearing surfaces which comprises maintaining between the hearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount suflicient to inhibit said corrosion, an aryl ester of. an orthophosphoric acid.

6. A method of lubricating bearing surfaces which comprises maintaining between the hearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount suflicient to inhibit said corrosion, a triaryl ester of an orthophosphoric acid.

7.-A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount suflicient to inhibit said corrosion, tricresyi phosphate.

8. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an efiective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount suflicient to inhibit said corrosion, an alkyl ester of an orthophosphoric acid.

9. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount sufficient to inhibit said corrosion, an alkyl acid-ester of an orthophosphoric acid.

10. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein, in an amount sufficient to inhibit said corrosion, a long chain alkyl acid-ester of an orthophosphoric acid.

11. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which isan alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil-by incorporating therein, in an amount sufl'icient' to inhibit said corrosion, a mixture of long chain alkyl acid-esters of an orthophosphoric acid.

12. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy formed chiefly of cadmium and silver, a film of lubricating oil which initially produces an elective lubricatin: action but which would normally tmd to corsurfaces. one of which in an alloy formed chiefly of cadmium and silver, I, film of lubricating oil which initially produces an elective lubricatina action but which would normally tend to corrode the aforesaid alloy, and maintaining the electivenesa' oi the lubricating oil by incorporating thirein, in an amount suiiicient to inhibit said corroaion, a mixture of tertiary amylpbenyl phoephatea.

ANTHONY l". BENNING.

'cxigmrcuz OF CORRECTION.

Patent No. 2,167,867.

August 1., 1959,;

ANTHONYIFRA'HCIS Bromine.

It in hereby certified that error ofthe above numbered patent requiring corrections: follows:

Signedand sealed this (Seal) 214th day or October,

Henry Van Arsda-le, Acting Commissioner of Patents. 

